JoachimSchwann is the tax collector in Novigrad. He is described as officious, fat and myopic, not to mention quite zealous about his duties. Geralt meets him during a scuffle with the local guards involving Dainty and Dudu in the short story "Wieczny ogień" ("The Eternal Fire").
Honorable Townsdwellers! I deeply regret to inform you about the untimely death of Joachim Schwann, a tax-collector who had served our fair city for many years. The ceremonial cremation of his remains will take place at the end of the current month.